Tanning material.



WILLY MOELLER, 0F HAMBURG, GERMANY, ASSIGNOR TO GERB- UND IEARBS'I'OIFF WERKE H. RENNER AND CO. AKTIENGESELLSGHAFT, OF HAMBURG, GERMANY.

TANNING MATERIAL.

No Drawing.

To all whom it may concern:

Be it known that I, WILLY MoELLEn, subject of the German Emperor, residing at Hamburg, Germany, have invented a certain new and useful Improvement Relating to Tanning Materials, of which the following is a specification.

The residual products which are produced in oilrefineries by the treatment of crude mineral oil with concentrated sulfuric acid, and which are known as acid resins, constitute as is well known, a troublesome waste,

for which hitherto no use has been found.

I have discovered, that these residual products contain substances, which possess in a high degree the property of forming leather and that the acid resins when relieved of free sulfuric acid in a suitable manner, constitute a very good tanning medium.

The acid resins, which constitute a sticky mass may be treated with the quantity of water necessary for their complete solution,

. after which the quantity of alkali or earthalkali or their carbonates, required for neutralizing the sulfuric acid, is added.

The solution is then relieved of the sulfate formed, either by crystallization or by clarification, according as an alkali or an earth alkali has been used for neutralization. The clear solutions thus obtained may be diluted in any desired degree or they may be concentrated and are perfectly mixable with vegetable and mineral tanning extracts. Be fore using the new tanning material the depilated hides are subjected to a preliminary treatment in the same manner as in other tanning processes. The conversion of the hide into leather may be effected either by the old pit-process or in the tanning vat. The tanning process may be combined with the vegetable or the mineral tanning process in any proportion. Leather obtained with the new tanning medium possesses great elasticity and resembles chromeleather as regards its physical properties.

The acid resins hereinabove referred to Specification of Letters Patent.

Patented Aug. 14, 1917.

Application filed July 19, 1913. Serial No. 780,023.

consist in the main of a mixture of true acid resins and free sulfuric acid. These true acid resins constitute a condensed sulfonated hydrocarbon, or a mixture of condensed sulfonated hydrocarbons. For the sake of clearness I shall, in my claims, refer to such true acid resins as acid resins, and to the mixture as acid resin sludge. WVhen I refer in the claims to the neutralization of the free acid I mean that'enough of the neutralizing substance is added to convert such free acid into a salt, but not so much as to destroy the identity of the true acid resins.

What I claim is 1. The process of tanning which includes the step of subjecting the material to be tanned to the action of acid-resins.

2. The process of tanning which includes the step of subjecting the material to be tanned to the action of a mixture of acidresins and a tanning extract.

3. The process of tanning which includes the step of subjecting the material to be tanned to the action of acid-resin sludge refined by the removal of the free acid.

4:. The process of tanning which includes the step of subjecting the material to be tanned to the action of acid-resin sludge refined by the neutralization of the free acid.

5. The process of tanning which includes the step of subjecting the material to be tanned to the action of acid-resin sludge the free acid in which has been neutralized by an alkali and the resulting salt removed.

6. The process of tanning which includes the step of subjecting the material to be tanned to the action of a condensed sulfonated hydrocarbon.

In testimony whereof I have hereunto set my hand in presence of two subscribing witnesses.

CARL BAUER,

MAX REINFTH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G. 

